<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.6.10/dist/vue.js"></script>
  </head>

  <body>
    <div id="app">
     <p>搜索 <input type="text" v-model="goodInfo.search"></p>
    </div>
    <script>
      Vue.config.productionTip = false;

      const vm = new Vue({
        el: "#app",
        data() {
          return {
            goodInfo:{
              search:"oppo",
              price:1888,
              num:10,
            }
          };
        },
        
      
       
        watch: {
          goodInfo:{
            // 立即监听
            immediate:true,
            // 深度监听
            deep:true,
            // 回调函数，接受两个参数，新值和旧值
            handler(newVal,oldVal){
              console.log("goodInfo 有变化",newVal,oldVal);
            }
          }
        },
      });
    </script>
  </body>
</html>
